Most manufacturers recommend mixing two bags at once. Yes, picking that up by yourself requires a fair amount of strength, but it's not bad at all with two people. And, if you are mixing it close to where you need it, you may not actually have to lift it at all! Cutting the start to finish time by half when mixing multiple bags at a time is a big benefit when trying to keep a wet edge, which is required to achieve a good job end result. It gets even more important as the summer approaches, and the water, material, and ambient conditions rise in temperature...that makes the chemical reaction work faster, giving you even less time between mixing and the stuff setting up or refusing to flow well. Use the coldest water you can, and don't leave the bags baking in the sun before you mix them up...heat is not your friend when using SLC. Well, super cold isn't either.

I get confused when I hear about a wet edge. I get that I may have to help it into corners and around the toilet flange. But, since I'm filling the whole room past the highest point (i.e. not worried about making a feathered edge), should I not simply keep pouring in the low area until the desired depth is achieved? Actually, no matter where I start/finish it seems that the first pour will have to be displaced in some way by the last and the finished height is not achieved anywhere until it is achieved everywhere (think of filling a large paint roller tray with 3 small cans of paint). Maybe I'm not conceptualizing this properly.

Some SLC will start to thicken as the result of curing in as little as 10-minutes, especially if it is warmer than the stated, typical 70-degree temperature. If you don't keep everything wetted, and you pour it all in the same place, you might just end up with a major hump there since it doesn't flow evenly on its own. Pour a batch, spread it around a little if needed, then when you pour the next batch, pour it at the edges so you always have a wet edge to work with. If you've moved and smoothed the first, the second can be tied to it. You actually pour it on the existing stuff, but near the edge. Assuming you start at the low point, you'd move out from there, but you can start at one end and continue to the other. It really helps if you can have someone else assisting, as one person mixing, pouring, moving the stuff, will have problems getting things installed before the first stuff is curing...you cannot successfully move stuff once it thickens as it starts to cure (well, it starts to cure as soon as it gets wet, but you won't notice it for a short bit as the properties change). Think pancake batter. Add some on the top of the original, and it won't extend to fill the pan, but you could add some around the wet edge and tie new to the old and maintain a consistent thickness. They make gauge rakes, smoothing tools, surface tension breakers (porcupine rollers), and while you can get by without buying these specialized tools, they do help. I got good use out of my snow rake to both move things around and as a smoother. Your results may differ! You have to get creative if you don't want to buy the specialized tools. And, speed is a prerequisite. If you try to smooth things after it has started to cure, it will make a mess.

Thanks for the advice. I think I get it now. I think I will practice mixing and spreading with one bag onto a test area that I'll make out of spare plywood; just to get a good feel for the stuff before taking the plunge. One tool I did buy is the spiked roller but I'm not totally sure if it's purpose. It's not the huge one but it's the size of a regular paint roller. I intend to use it to push the SLC around and into the corners and to do a once over at the end to break any remaining surface tension. Thanks again.

The spiked rollers break the surface tension, and that helps it even itself out. Often, on a big pour, it works best to use a gauge rake...it's a screed with feet that you adjust to get the majority of the pour a single thickness...then, if you go over it with the spiked roller, it helps it flow from the areas where it is sitting over a hill to the lower areas and level. Last, you'd use the smoother to literally smooth out any surface imperfections...you skim it across the surface with light pressure.

You could make yourself a gauge rake easily...take a piece of 1x or 2x material, screw a couple of nails into an edge so it is the right height, and attach a handle. Once you've poured the SLC, run that over it. That will make the pour essentially all the same depth. Obviously, if that were enough, you wouldn't need the slc...then, you need to get it to flow more easily from the high points to the lower ones to fill in...this is where the spiked roller helps. Finally, smooth it all out (you might end up using the other, smooth edge of your cobbled up gauge rake). The dedicated tools are easier to use over a large area, but you can do it without them. Just pouring slc and expecting it to level doesn't usually work...it needs some help.

Before I get started tiling I thought I should make a few test cuts to assess the blade/saw quality. I don't plan on using any schluter strips or bull nose so it's important for the perimeter and around the niche that I'm able to minimize chipping. I don't have a professional frame of reference to tell if what I've achieved is good or bad so I'm hopeful that someone can offer an assessment of these test cuts. I'm using the Harbor Freight 10" wet saw and the blade pictured below. Thoughts? By the way it seems that most of this chipping is being caused by the blade as it goes back up. I have the depth at exactly the thickness of the tile (7/16").

The blade is going down into the tile as I push the tray through. Then the back of the blade goes up as it exits the tile. That's when most of the chipping occurs. Can you tell by the pictures whether this is within acceptable professional standards?

The following is my current plan of attack for installing self leveling concrete (Mapei Self-Leveler Plus). First, a brief description and terrible drawing of the problem:

About 60 sqft concrete slab that slopes about 5/8" from the high ridge (see dotted line) to the opposing wall (a distance of 73", following the arrows in my very crude rendering). I've calculated it will take about 7.25 bags to raise the whole floor to 3/8" higher than the high ridge.

Call me crazy (I hope not) but I think I can tackle this on my own. Here's how:

1) Using the blue 15 gal mixing barrel and a box style mixing paddle (and new big drill), mix two bags together and pour along the lowest area (after appropriately priming and damming/sealing). Hit it with the spiked roller.

2) Let cure 24 hours. Re-prime.

3) Using the same 15 gal barrel, mix 3 bags together and pour over the same area as in step one (which will still be the lowest area). Repeat with remaining 3 bags together in blue barrel and pour onto wet edge of previous pour (flooding the whole room to the desired 3/8" to 1/2" above the high ridge).

The purpose of breaking this into two days is so I will only have to mix two batches of SLC one after the other instead of three, giving me a critical few (4) minutes after I'm done mixing and pouring said two batches to spread/push the SLC around the whole floor while it's still in its liquid state.

I understand that three bags SLC plus water will be pushing 200 lbs. Before adding materials to barrel I'll strap it securely to a furniture dolly which should allow me to move it a few feet and tip the thing over.

So, we're in agreement that this is a well reasoned approach? Any critiques would be greatly appreciated. Thank you as always.

Dang. I had a feeling that might be the response. Question then, in that scenario, by the time I finish mixing the 3rd batch, the 1st batch will have been in contact with water going on 9 min. With a 10 min flow time would I not risk that first batch firming up to much before it has there opportunity to meld with the last batch? I would be more comfortable with that if I were only attempting to flatten (not also level) the floor, in which case the first batch wouldn't necessarily be disturbed by the last. Thoughts?